oracle 23c free DB + langchain sql query chain

[neerajsingh4736]

I am having issues with working with create sql query chain and Oracle 23c free DB . Please help , below is my code.
from langchain.chains import create_sql_query_chain
from langchain_openai import ChatOpenAI
from sqlalchemy import create_engine, MetaData

llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0)

Get database credentials

username = 'HR'
hostname = 'localhost'
port = '1521'
service_name = 'freepdb1'
password = getpass.getpass(f'Enter password for {username}@{hostname}/{service_name}: ')

Construct connection string with service name

connection_string = f'oracle+cx_oracle://{username}:{password}@{hostname}:{port}/?service_name={service_name}'

Create SQLAlchemy engine

engine = create_engine(connection_string)

Create SQLAlchemy connection

connection = engine.connect()

Create metadata object and bind it to the engine

metadata = MetaData(bind=engine)

Reflect database tables

metadata.reflect()

Extract table names

table_names = metadata.tables.keys()

Create SQL query chain

chain = create_sql_query_chain(llm, connection)

Invoke the chain with the question

response = chain.invoke({"question": "How many employees are there"})
print(response)